Today's social liberalism is tomorrow's social moderation. This is kind of how it works. The Republicans will eventually accept marriage equality and abortion rights, but it'll be a long time from now, and by that point, the Democrats will have already moved more to the left on whatever the social issues are of the day, assuming the Democrats remain the more progressive of the two parties, that is.
Gay right, I can understand, but why would you think that the abortion is inevitably going to be accepted?
Because women will probably make up the majority of legislators at some point, as they already comprise the majority of voters and play a large role at least in the Democratic coalition.
